It's wonderful that churches, schools, and business have
made themselves accessible to the visible minority of people
in wheelchairs. For less money, they can also make themselves
optimally accessible to the large but largely invisible minority
of people with hearing loss--some 37.5 million Americans according
to the National
Institute on Deafness and Other Communication Disorders.
About 1 in 4--some 8.4
million--have hearing aids, a number that would
surely increase if hearing aids could double as wireless,
customized loudspeakers.

In most places, hard of hearing people hear the broadcast
sound, but only after it has traveled some distance from a
loudspeaker, reverberated off walls, and gotten mixed with
other room noise. Induction loop systems take sound straight
from the source and deliver it right into the listener's head.
It's as if one's head was located in the microphone, or inches
from a television's loudspeaker--without extraneous noise,
or blurring of the sound with distance from the sound source.